This invention concerns a multi-pole circuit breaker with molded case and static tripping unit, comprising an electronic device to process the signals delivered by current transformers associated with each pole, which electronic processing device is part of a subassembly inserted in a compartment of the molded case and delivers a tripping signal to a tripping coil in the case of an overload or a short-circuit.
A prior art circuit breaker of this kind comprises a sealed housing for the electronic part of the static tripping unit, which housing is lodged in removable fashion inside the molded case of the circuit breaker. The housing is sealed so that none of the circuit breaking gases can penetrate to damage the electronic part inside the housing. The housing is located near the circuit breaker current transformers and power conductors and is subjected to considerable heating that may affect the correct operation of the tripping unit.
The aim of this invention is to eliminate this disadvantage and to provide a static circuit breaker that will operate reliably in all circumstances.